Problem with getting linear output of a temperature sensor

[ashad]

Hi all,

i am new in the Field of DSP, i have temperature sensor but the output of the sensor is exponentialy decreasing i want linear output

some suggest me that u use A- law or Mu-law i don't know any thing about that.... please advice me that is it the only solution and how i implement it

thnx

 

[mayyan]

Re: please help me

y = a*e^(bx)

y/a = e^(bx)

z:= ln(y/a) = bx

and we are linear now . i also advice you to search for: linear regression, heat covection, heat transfer.

regards
mayyan

 

[III]

please help me

well this has little to do with dsp but the value of the voltage of the emyter layer of a directly polarized npn is a linear fnction of temperature (with in reasnoble walues)

 

[ashad]

Re: please help me

y = a*e^(bx)

y/a = e^(bx)

z:= ln(y/a) = bx

and we are linear now . i also advice you to search for: linear regression, heat covection, heat transfer.

regards
mayyan

it is good idea but i can't implement on Hardware ..... so i used an other circuit to linearized the sensor output but due to ur efforts i give u 3 points.....

 

[ebook123456789]

Re: please help me

a very simple yet efficient way to implement this is to use LUT. I assume your table does not have too much entries. all the computation are done beforehand so it is very fast and easy. the only drawback may be use some memory.

 

[IBO]

Re: please help me

use a look up table

 

[spikeyang]

please help me

Use a log-amplifier.

 

[pronab]

Re: please help me

felling well